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Ji C, He T, Wu B, Cao X, Fan X, Liu X, Li X, Yang M, Wang J, Xu L, Hu S, Xia L, Sun Y. Identification and characterization of a novel type II toxin-antitoxin system in Aeromonas veronii. Arch Microbiol 2024; 206:381. [PMID: 39153128 DOI: 10.1007/s00203-024-04101-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Accepted: 08/02/2024] [Indexed: 08/19/2024]
Abstract
The bacterial type II toxin-antitoxin (TA) system is a rich genetic element that participates in various physiological processes. Aeromonas veronii is the main bacterial pathogen threatening the freshwater aquaculture industry. However, the distribution of type II TA system in A. veronii was seldom documented and its roles in the life activities of A. veronii were still unexplored. In this study, a novel type II TA system AvtA-AvtT was predicted in a fish pathogen Aeromonas veronii biovar sobria with multi-drug resistance using TADB 2.0. Through an Escherichia coli host killing and rescue assay, we demonstrated that AvtA and AvtT worked as a genuine TA system, and the predicted toxin AvtT actually functioned as an antitoxin while the predicted antitoxin AvtA actually functioned as a toxin. The binding ability of AvtA with AvtT proteins were confirmed by dot blotting analysis and co-immunoprecipitation assay. Furthermore, we found that the toxin and antitoxin labelled with fluorescent proteins were co-localized. In addition, it was found that the transcription of AvtAT bicistronic operon was repressed by the AvtAT protein complex. Deletion of avtA gene and avtT gene had no obvious effect on the drug susceptibility. This study provides first characterization of type II TA system AvtA-AvtT in aquatic pathogen A. veronii.
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Affiliation(s)
- Caihong Ji
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, 410081, P. R. China
| | - Ting He
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, 410081, P. R. China
| | - Binbin Wu
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, 410081, P. R. China
| | - Xiaomei Cao
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, 410081, P. R. China
| | - Xiaping Fan
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, 410081, P. R. China
| | - Xia Liu
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, 410081, P. R. China
| | - Xiaodan Li
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, 410081, P. R. China
| | - Miao Yang
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, 410081, P. R. China
| | - Jihan Wang
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, 410081, P. R. China
| | - Ling Xu
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, 410081, P. R. China
| | - Shengbiao Hu
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, 410081, P. R. China
| | - Liqiu Xia
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, 410081, P. R. China
| | - Yunjun Sun
- State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, 410081, P. R. China.
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Li Y, Sun Z. Phenotypic and genomic insights into the pathogenicity and antimicrobial resistance of an Enterobacter roggenkampii strain isolated from diseased silver arowana (Osteoglossum bicirrhosum). JOURNAL OF FISH DISEASES 2024; 47:e13898. [PMID: 38014710 DOI: 10.1111/jfd.13898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 11/14/2023] [Accepted: 11/17/2023] [Indexed: 11/29/2023]
Abstract
Enterobacter roggenkampii is an opportunistic pathogen that causes infections in a wide range of hosts. A bacterial strain named EOBSR_19 was isolated from diseased silver arowana, Osteoglossum bicirrhosum. This bacterium was identified as E. roggenkampii based on the phenotypic characteristics and sequence analysis of the16S rDNA and gyrB genes. Average nucleotide identity and phylogenetic analysis based on the whole genome sequence further confirmed the bacterial taxonomy of EOBSR_19. Artificial experimental infection indicated that EOBSR_19 was pathogenic to fish. Antimicrobial susceptibility test showed it was multi-drug resistant. The EOBSR_19 was found to be resistant to 18 antibiotics belonging to quinolones, macrolides, sulfonamides, aminoglycosides, and β-lactams classes. The whole genome sequencing analysis showed that EOBSR_19 carried 730 virulence genes that were annotated for different functional modules, such as adhesion and invasion, secretion system, siderophore transport system and bacterial toxin. Among them, the virulence genes related to adhesion and invasion were the most abundant. In addition, drug resistance genes involved in multiple mechanisms of antimicrobial resistance were identified in its genomics, including multidrug resistance efflux pumps, antibiotic inactivating enzymes, and antibiotic binding site mutations. Its genomic analysis via whole-genome sequencing provided insights into the pathogenicity and antimicrobial resistance.
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Affiliation(s)
- Yuerui Li
- Tianjin Key Laboratory of Aqua-ecology and Aquaculture, Fisheries College, Tianjin Agricultural University, Tianjin, China
| | - Zhongshi Sun
- Tianjin Key Laboratory of Aqua-ecology and Aquaculture, Fisheries College, Tianjin Agricultural University, Tianjin, China
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Bispo dos Santos S, Fernandez Alarcon M, Ballaben AS, Harakava R, Galetti R, Guimarães MC, Natori MM, Takahashi LS, Ildefonso R, Rozas-Serri M. First Report of Aeromonas veronii as an Emerging Bacterial Pathogen of Farmed Nile Tilapia ( Oreochromis niloticus) in Brazil. Pathogens 2023; 12:1020. [PMID: 37623980 PMCID: PMC10459805 DOI: 10.3390/pathogens12081020] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 07/31/2023] [Accepted: 08/04/2023] [Indexed: 08/26/2023] Open
Abstract
Brazil is one of the world's leading producers of Nile tilapia, Oreochromis niloticus. However, the industry faces a major challenge in terms of infectious diseases, as at least five new pathogens have been formally described in the last five years. Aeromonas species are Gram-negative anaerobic bacteria that are often described as fish pathogens causing Motile Aeromonas Septicemia (MAS). In late December 2022, an epidemic outbreak was reported in farmed Nile tilapia in the state of São Paulo, Brazil, characterized by clinical signs and gross pathology suggestive of MAS. The objective of this study was to isolate, identify, and characterize in vitro and in vivo the causative agent of this epidemic outbreak. The bacterial isolates were identified as Aeromonas veronii based on the homology of 16S rRNA (99.9%), gyrB (98.9%), and the rpoB gene (99.1%). A. veronii showed susceptibility only to florfenicol, while it was resistant to the other three antimicrobials tested, oxytetracycline, enrofloxacin, and amoxicillin. The lowest florfenicol concentration capable of inhibiting bacterial growth was ≤0.5 µg/mL. The phenotypic resistance of the A. veronii isolate observed for quinolones and tetracycline was genetically confirmed by the presence of the qnrS2 (colE plasmid) and tetA antibiotic-resistant genes, respectively. A. veronii isolate was highly pathogenic in juvenile Nile tilapia tested in vivo, showing a mortality rate ranging from 3 to 100% in the lowest (1.2 × 104) and highest (1.2 × 108) bacterial dose groups, respectively. To our knowledge, this study would constitute the first report of highly pathogenic and multidrug-resistant A. veronii associated with outbreaks and high mortality rates in tilapia farmed in commercial net cages in Brazil.
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Affiliation(s)
- Sandie Bispo dos Santos
- Pathovet Labs, Ribeirão Preto 14025-020, Brazil; (S.B.d.S.); (M.F.A.); (R.G.); (M.C.G.); (M.M.N.); (R.I.)
| | - Miguel Fernandez Alarcon
- Pathovet Labs, Ribeirão Preto 14025-020, Brazil; (S.B.d.S.); (M.F.A.); (R.G.); (M.C.G.); (M.M.N.); (R.I.)
| | - Anelise Stella Ballaben
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo 14040-020, Brazil;
| | | | - Renata Galetti
- Pathovet Labs, Ribeirão Preto 14025-020, Brazil; (S.B.d.S.); (M.F.A.); (R.G.); (M.C.G.); (M.M.N.); (R.I.)
| | - Mateus Cardoso Guimarães
- Pathovet Labs, Ribeirão Preto 14025-020, Brazil; (S.B.d.S.); (M.F.A.); (R.G.); (M.C.G.); (M.M.N.); (R.I.)
| | - Mariene Miyoko Natori
- Pathovet Labs, Ribeirão Preto 14025-020, Brazil; (S.B.d.S.); (M.F.A.); (R.G.); (M.C.G.); (M.M.N.); (R.I.)
| | - Leonardo Susumu Takahashi
- Departamento de Produção Animal, Faculdade de Ciências Agrárias e Tecnológicas, Universidade Estadual Paulista, Dracena, São Paulo 17900-000, Brazil;
| | - Ricardo Ildefonso
- Pathovet Labs, Ribeirão Preto 14025-020, Brazil; (S.B.d.S.); (M.F.A.); (R.G.); (M.C.G.); (M.M.N.); (R.I.)
- Pathovet Labs, Puerto Montt 5550000, Chile
| | - Marco Rozas-Serri
- Pathovet Labs, Ribeirão Preto 14025-020, Brazil; (S.B.d.S.); (M.F.A.); (R.G.); (M.C.G.); (M.M.N.); (R.I.)
- Pathovet Labs, Puerto Montt 5550000, Chile
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Maia JCDS, Silva GADA, Cunha LSDB, Gouveia GV, Góes-Neto A, Brenig B, Araújo FA, Aburjaile F, Ramos RTJ, Soares SC, Azevedo VADC, Costa MMD, Gouveia JJDS. Genomic Characterization of Aeromonas veronii Provides Insights into Taxonomic Assignment and Reveals Widespread Virulence and Resistance Genes throughout the World. Antibiotics (Basel) 2023; 12:1039. [PMID: 37370358 DOI: 10.3390/antibiotics12061039] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 05/23/2023] [Accepted: 06/09/2023] [Indexed: 06/29/2023] Open
Abstract
Aeromonas veronii is a Gram-negative bacterial species that causes disease in fish and is nowadays increasingly recurrent in enteric infections of humans. This study was performed to characterize newly sequenced isolates by comparing them with complete genomes deposited at the NCBI (National Center for Biotechnology Information). Nine isolates from fish, environments, and humans from the São Francisco Valley (Petrolina, Pernambuco, Brazil) were sequenced and compared with complete genomes available in public databases to gain insight into taxonomic assignment and to better understand virulence and resistance profiles of this species within the One Health context. One local genome and four NCBI genomes were misidentified as A. veronii. A total of 239 virulence genes were identified in the local genomes, with most encoding adhesion, motility, and secretion systems. In total, 60 genes involved with resistance to 22 classes of antibiotics were identified in the genomes, including mcr-7 and cphA. The results suggest that the use of methods such as ANI is essential to avoid misclassification of the genomes. The virulence content of A. veronii from local isolates is similar to those complete genomes deposited at the NCBI. Genes encoding colistin resistance are widespread in the species, requiring greater attention for surveillance systems.
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Affiliation(s)
- José Cleves da Silva Maia
- Graduate Program in Animal Science, Agricultural Sciences Campus, Federal University of Vale of São Francisco (Univasf), Petrolina 56304-917, Pernambuco, Brazil
- Center for Open Access Genomic Analysis (CALAnGO), Federal University of Vale of São Francisco (Univasf), Petrolina 56304-917, Pernambuco, Brazil
| | - Gabriel Amorim de Albuquerque Silva
- Center for Open Access Genomic Analysis (CALAnGO), Federal University of Vale of São Francisco (Univasf), Petrolina 56304-917, Pernambuco, Brazil
| | - Letícia Stheffany de Barros Cunha
- Graduate Program in Animal Science, Agricultural Sciences Campus, Federal University of Vale of São Francisco (Univasf), Petrolina 56304-917, Pernambuco, Brazil
- Center for Open Access Genomic Analysis (CALAnGO), Federal University of Vale of São Francisco (Univasf), Petrolina 56304-917, Pernambuco, Brazil
| | - Gisele Veneroni Gouveia
- Center for Open Access Genomic Analysis (CALAnGO), Federal University of Vale of São Francisco (Univasf), Petrolina 56304-917, Pernambuco, Brazil
| | - Aristóteles Góes-Neto
- Laboratory of Molecular Computational Biology of Fungi (LBMCF), Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte 31270-901, Minas Gerais, Brazil
| | - Bertram Brenig
- Institute of Veterinary Medicine, University of Göttingen, 37077 Göttingen, Niedersachsen, Germany
| | - Fabrício Almeida Araújo
- Biological Engineering Laboratory, Institute of Biological Sciences, Federal University of Pará (UFPA), Belém 66075-110, Pará, Brazil
| | - Flávia Aburjaile
- Preventive Veterinary Medicine Department, Veterinary School, Federal University of Minas Gerais, Belo Horizonte 31270-901, Minas Gerais, Brazil
| | - Rommel Thiago Jucá Ramos
- Biological Engineering Laboratory, Institute of Biological Sciences, Federal University of Pará (UFPA), Belém 66075-110, Pará, Brazil
| | - Siomar Castro Soares
- Department of Microbiology, Immunology, and Parasitology, Federal University of Triângulo Mineiro, Uberaba 38025-180, Minas Gerais, Brazil
| | - Vasco Ariston de Carvalho Azevedo
- Laboratory of Cellular and Molecular Genetics (LGCM), Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte 31270-901, Minas Gerais, Brazil
| | - Mateus Matiuzzi da Costa
- Center for Open Access Genomic Analysis (CALAnGO), Federal University of Vale of São Francisco (Univasf), Petrolina 56304-917, Pernambuco, Brazil
| | - João José de Simoni Gouveia
- Center for Open Access Genomic Analysis (CALAnGO), Federal University of Vale of São Francisco (Univasf), Petrolina 56304-917, Pernambuco, Brazil
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Song H, Yang B, Kang Y, Cong W. Critical roles of VipB protein on virulence and oxidative stress tolerance in Aeromonas veronii. JOURNAL OF FISH DISEASES 2023; 46:487-497. [PMID: 36708291 DOI: 10.1111/jfd.13760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 01/01/2023] [Accepted: 01/10/2023] [Indexed: 06/18/2023]
Abstract
Aeromonas veronii is a zoonotic pathogen capable of causing sepsis and ulceration in freshwater fish. Recently, reports of numerous cases indicate a marked increase in pathogenicity. Nonetheless, little is known about the pathogenesis of A. veronii infections. In this study, an in-frame mutant of the A. veronii vipB gene was generated to investigate its biological function. Deletion of the vipB gene resulted in a significant 204.71-fold decrease in the LD50 of A. veronii against zebrafish and a 2-fold and 4-fold reduction in the toxicity to EPC cells at 1 h and 2 h of infection, respectively. The virulence-related genes of the mutant ΔvipB all showed significantly reduced expression levels compared to the wild strain. In addition, the motility of the mutant ΔvipB decreased significantly, the adhesion ability to EPC cells was 3.25-fold lower than that of the parental strain, and the oxidative stress tolerance was 2.31-fold lower than that of TH0426 strain. In contrast, the biofilm formation amount of ΔvipB strain increased by 1.65-fold at both 12 h and 24 h. Our findings suggest that the vipB gene is associated with flagella stability, virulence, and oxidative stress tolerance and plays critical roles in the pathogenesis of A. veronii infections.
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Affiliation(s)
- Haichao Song
- Marine College, Shandong University, Weihai, China
| | - Bintong Yang
- Marine College, Shandong University, Weihai, China
| | | | - Wei Cong
- Marine College, Shandong University, Weihai, China
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Mu Q, Dong Z, Kong W, Wang X, Yu J, Ji W, Su J, Xu Z. Response of immunoglobulin M in gut mucosal immunity of common carp ( Cyprinus carpio) infected with Aeromonas hydrophila. Front Immunol 2022; 13:1037517. [PMID: 36466906 PMCID: PMC9713697 DOI: 10.3389/fimmu.2022.1037517] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 11/03/2022] [Indexed: 12/01/2023] Open
Abstract
Immunoglobulin (Ig) M is an important immune effector that protects organisms from a wide variety of pathogens. However, little is known about the immune response of gut mucosal IgM during bacterial invasion. Here, we generated polyclonal antibodies against common carp IgM and developed a model of carp infection with Aeromonas hydrophila via intraperitoneal injection. Our findings indicated that both innate and adaptive immune responses were effectively elicited after A. hydrophila infection. Upon bacterial infection, IgM+ B cells were strongly induced in the gut and head kidney, and bacteria-specific IgM responses were detected in high levels both in the gut mucus and serum. Moreover, our results suggested that IgM responses may vary in different infection strategies. Overall, our findings revealed that the infected common carp exhibited high resistance to this representative enteropathogenic bacterium upon reinfection, suggesting that IgM plays a key role in the defense mechanisms of the gut against bacterial invasion. Significantly, the second injection of A. hydrophila induces strong local mucosal immunity in the gut, which is essential for protection against intestinal pathogens, providing reasonable insights for vaccine preparation.
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Affiliation(s)
- Qingjiang Mu
- Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Zhaoran Dong
- Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Weiguang Kong
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, China
| | - Xinyou Wang
- Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan, Hubei, China
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, China
| | - Jiaqian Yu
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, China
- College of Fisheries and Life Science, Dalian Ocean University, Dalian, China
| | - Wei Ji
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, China
| | - Jianguo Su
- Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Zhen Xu
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
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